The PC industry worldwide sold 136 million desktop PCs last year, along with 160 million traditional notebooks driven by keyboards and touchpads. Those big numbers explain why Microsoft is feverishly improving the desktop experience for "the next iteration of Windows."

I've already railed against Apple's overhaul of iOS 7, with its jarring use of white and its over-reliance on textual Web motifs. But, as the rest of the software industry follows suit – and as Microsoft and Apple blur the boundaries between tablet and desktop user interfaces – it's worth asking if the user experience really is improving.